Re: [PATCH v2 6/9] n_tty: Process echoes in blocks

From: Greg Kroah-Hartman
Date: Tue Jul 23 2013 - 19:53:36 EST


On Sat, Jun 15, 2013 at 10:04:26AM -0400, Peter Hurley wrote:
> Byte-by-byte echo output is painfully slow, requiring a lock/unlock
> cycle for every input byte.
>
> Instead, perform the echo output in blocks of 256 characters, and
> at least once per flip buffer receive. Enough space is reserved in
> the echo buffer to guarantee a full block can be saved without
> overrunning the echo output. Overrun is prevented by discarding
> the oldest echoes until enough space exists in the echo buffer
> to receive at least a full block of new echoes.

I'm a bit worried about this, I wonder if anything is expecting the
echos to not come in "bursts" like this, but I really can't think of why
they would want that.

So let's apply it and see what breaks! :)

thanks,

greg k-h
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